Bolt.



E. I. 0000s.

BOLT.

Patented Aug. 7, 1917.

WWW

IITED TAT ATEN Q.

ETHAN I. DODDS, OF ZPITTSBURGH, PENNSYLVANIA, ASSIGNOB, TO FLANNERY BOLT COMPANY, OF PITTSBURGH, PENNSYLVANIA.

BOLT.

Specification of Letters Patent.

Patented Aug. 7, 1917.

Application filed March 12, 1915. Serial No. 13,884.

T 0 all whom it may concern:

Be it known that I, ETHAN I. Donns, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Bolts; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improvement in bolts designed more particularly for railroad track construction, the object being to provide a bolt capable of slight elongation or spring action longitudinally, and which will resume its normal length after the stress has been removed, thus preventing the metal in the bolt from becoming permanently set, and removing, to a large extent the tendency of the nuts to work loose.

WVith these objects in view my invention consists in the details of construction as will be more fully explained and pointed out in the claims.

In the accompanying drawings, Figure 1- is a view in elevation of a bolt embodying my invention; Fig. 2 is an end elevation of the same; Fig. 3 is a view in longitudinal section on the line :0 00 of Fig. 2. Fig. 4 is a view in longitudinal section of the bolt after the slots have been closed; Fig. 5 is a view of the bolt shank twisted, and Figs. 6 to 9 inclusive are views of a modified form of bolt.

In the manufacture of the bolt, a round bar of steel is headed in dies in the usual manner, and while it is hot from the original heating or reheating, it is slotted, throughout its length including its head, at diametrically opposite points as shown in Fig. 2. The slots 1 inthe head 2, and the opposite end 8 and at one or more points intermediate the ends, do not extend all the way through, but stop short of the center leaving the integral connections or fuses 4 which retain the two parts of the bolt in proper relative position, the portion of the bolt intermediate these connections or fuses being slotted all the way through as shown in Fig. 3. These slots may be formed by cutting, punching or in the process of rolling the blank, but if out or punched, I prefer to do it with a tool that simply expands the blank without removing any of the metal. The slots thus formed are closed between dies or other tools, w thout welding the walls of the slots and this blank or bolt thus formed is twisted about a quarter turn so that the closed slots are in the form of spirals each extending approxnnately 90 around the bolt shank, after which the threads are formed. These threads may be hot or cold rolled, or they may be cut, but in either event they are formed after the bolt shank has been twisted.

Instead of slotting the bolt throughout its ent1re length and leaving connecting fuses at the center only, I may slot the bolt all the way through at both sides of the center of the shank, leaving the free end of the bolt and outer end of head intact as shown in Figs. 6 to 9 inclusive. This latter method of slotting leaves a central fuse and two end fuses 4, each as wide as the bolt, but preferably narrower than those shown in Fig. 1.

During the process of manufacture, and before or after the threads have been cut, I prefer to temper the bolts in oil so as to increase their hardness without afiecting their elasticity.

A steel bolt slotted and twisted as described is capable of slight elongation which permits it to yield or give under the pounding of the wheels on the rails at the joints, and immediately goes back to normal length as soon as the strains are relieved. This prevents permanent elongation of the bolt, and maintains the nut at all times under a pressure sufiicient to prevent it from turning, as it does on ordinary bolts after usage sufficient to cause a slight elongation of the bolt. By constructing the bolt so that it will give under stress and then go back to normal length, the nut will always be under the original pressure to which it was subjected when applied to the bolt.

While I have designed the bolt for railroad track construction, it may be used for other purposes where an extensible or resilient bolt is desirable.

While the exact sequence of steps may not be essential, I prefer to subject the bar or blank to a mellow heat and then shape it in dies or other suitable tools to produce an enlarged head. The shank of the bolt is then pierced or slotted, after which the slots or impiercements are closed, the shank twisted and the bolt smoothed, straightened and threaded.

Having fully described my invention what I claim as new and desire to secure by Letters-Patent, is v 1. A bolt the shank of which is slotted all the way through and a connection or fuse integral with the members of the bolt intermediate the ends of the slots, the slots at the two sides of the integral connection being of greater length than the width of the connection.

2. A bolt slotted all the way through intermediate its center and ends, and part way through at the center and both ends.

Copies of this patent may be obtained for 3. A bolt slotted all the way through intermediate its center and ends and part way through at the center and both ends, the shank of the bolt being twisted and threaded.

In testimony whereof, I have signed this specification in the presence of two subscribing witnesses.

ETHAN I. DoDDs.

Witnesses F. H. ALL'IsoN, EDWIN S. RYCE;

five cents each; by adiiress'ing the Commissioner of Patents; Washington, D. G. i 

